/*
 * Copyright 2018 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */


#ifndef GrGradientBitmapCache_DEFINED
#define GrGradientBitmapCache_DEFINED

#include "include/core/SkBitmap.h"
#include "include/effects/SkGradientShader.h"
#include "include/private/SkColorData.h"
#include "include/private/base/SkMutex.h"
#include "include/private/base/SkNoncopyable.h"

class SkColorSpace;

class GrGradientBitmapCache : SkNoncopyable {
public:
    GrGradientBitmapCache(int maxEntries, int resolution);
    ~GrGradientBitmapCache();

    // Assumes colors are compatible with the specified alphaType (e.g. if it's premul then colors
    // are already premultiplied). Thread safe.
    void getGradient(const SkPMColor4f *colors, const SkScalar *positions, int count, bool colorsAreOpaque,
        const SkGradientShader::Interpolation &interpolation, const SkColorSpace *intermediateColorSpace,
        const SkColorSpace *dstColorSpace, SkColorType colorType, SkAlphaType alphaType, SkBitmap *bitmap);

private:
    SkMutex fMutex;

    int fEntryCount;
    const int fMaxEntries;
    const int fResolution;

    struct Entry;
    mutable Entry *fHead;
    mutable Entry *fTail;

    inline Entry *release(Entry *) const;
    inline void attachToHead(Entry *) const;

    bool find(const void *buffer, size_t len, SkBitmap *) const;
    void add(const void *buffer, size_t len, const SkBitmap &);

    void fillGradient(const SkPMColor4f *colors, const SkScalar *positions, int count, bool colorsAreOpaque,
        const SkGradientShader::Interpolation &interpolation, const SkColorSpace *intermediateColorSpace,
        const SkColorSpace *dstColorSpace, SkBitmap *bitmap);

#ifdef SK_DEBUG
    void validate() const;
#else
    void validate() const {}
#endif

    class AutoValidate : SkNoncopyable {
    public:
        AutoValidate(const GrGradientBitmapCache *bc) : fBC(bc)
        {
            bc->validate();
        }
        ~AutoValidate()
        {
            fBC->validate();
        }

    private:
        const GrGradientBitmapCache *fBC;
    };
};

#endif
